Wix Pay API - Quantity Example

Hello, all. Can someone PLEASE share the BACKEND code and the CLIENT SIDE code for collecting payments based on QUANTITY? For example, I need my clients to pay $25 per page for my Standard Editing service (createStandardEditingPayment). The relevant elements on the order form are the quantity input field where users can type in a number from 1-5 ( #pgsInput ) and ONE button (buttonEditsConfirmPay). The button will be used to submit the order form details to the editRequests database and to send the user to the payment form.